The invention relates to an apparatus and a method for automating treadmill therapy for rehabilitating walking-disabled patients.
During treadmill therapy, patients (e.g., paraparetic patients or patients after a stroke) are trained on a treadmill. For this purpose, they are suspended on a special suspension device above the treadmill. On the one hand, this makes it possible to relieve part of their body weight and otherwise they need to be concerned only a small amount about maintaining their balance. Especially during the initial time after the injury, the patient is often not able at all to move his legs himself. As a result, physiotherapists must keg guide the patients"" legs. If intensive training is performed on the patients as soon as possible after injury, special movement centers in the spinal chord of the patient are trained again, and the patient will learn to walk better than is possible with conventional forms of therapy. This guidance of the legs is very exhausting work for the therapists, and they tire relatively quickly when performing this training. Because of this, the training units often are too short, and the results of the therapy are less than optimal.
This training can be automated with the machine described here. This machine is an orthotic device driven at the knee and hip joints, which can be adapted to any patient. During training, the legs of the patient are guided by the orthotic device in a physiological sequence of movement. In contrast to the manually guided therapy, greater success can be achieved with the automated therapy because the training units can be performed as long as desired. It is possible to perform intensive training very soon after the patient is injured. Therapy with the driven orthotic device also requires only one therapist to caring for the patient, i.e., less personnel is needed.
Treadmill therapy is now commonly used in many areas when treating patients with neurological diseases. It is especially often used in paraplegic centers, and has been scientifically proven in this context. Therapy currently takes place on a treadmill where the patients are suspended with a belt, and their legs are guided by two physiotherapists (I. Wickelgren, Teaching the spinal cord to walk, Science, 1998, Vol. 279, 319-321). With the help of regular treadmill training, paraparetic patients and patients after a stroke are able to relearn walking much faster and better. Different orthotic devices are already being used in the rehabilitation of patients who have movement restrictions of the legs. Passive walking orthotic devices as described, for example, in U.S. 5,320,590 (1994), are already being used regularly in the rehabilitation of paraplegics. There are already several approaches for driven orthotic devices. U.S. Pat. No. 5,020,790 (1991) and GB 2260495 (1991) describe some of these, in which knee and hip joints are driven with hydraulic cylinders or electric motors. By using these orthotic devices, it is possible to move the legs of a patient for whom the respective orthotic device has been specifically manufactured in a movement pattern similar to walking.
Patent application EP 0782843 A2 (1996) describes an orthotic device that is also driven at the knee and hip joints. However, the patient undergoes his training on a treadmill. The leg movements are controlled via switches that the patient manually activates during walking and which bring about an extension or flexion of the leg.
It is the task of the invention at hand to automate the previously manual treadmill training for patients in rehabilitation.
According to the invention, this objective is realized with a driven orthotic device and an associated method for operating the orthotic device as described herein.
At issue is the guidance of the legs of a patient positioned above the treadmill in a walking pattern that as is as physiological as possible. This requires a control of the drives that regulate these drives according to a predetermined sequence of movement. The patient should be stabilized on the treadmill in such a way that he need not be concerned about his balance. This means he can concentrate on a dynamic, physiological walking pattern.
The orthotic device should be usable in the rehabilitation centers for training different patients and therefore must be adjustable in size and shape. The orthotic device must be designed so that no pressure points can be created on the patient""s body since paraplegics, in particular, quickly develop pressure ulcers.
The invention is explained in more detail below in reference to the drawings.
FIG. 1 shows a schematic portrayal of the principle of treadmill training with driven orthotic device, where the fixation is accomplished with a parallelogram;
FIG. 2 shows the parallelogram for fixing the driven orthotic device on the treadmill;
FIG. 3 shows a schematic portrayal of the principle of treadmill training with driven orthotic device, where the fixation is accomplished with a roller guide;
FIG. 4 shows the roller guide for fixing the driven orthotic device on the treadmill;
FIG. 5 shows an overall view of the driven orthotic device;
FIG. 6 shows a view of the adjustable hip orthotic device;
FIG. 7 shows an exemplary embodiment of a knee drive with ball screw spindle;
FIG. 8 shows an exemplary embodiment of a cuff for fixing the legs;
FIG. 9 shows an overview of the control of the therapy system; and
FIG. 10 shows the control unit.